Is Having A Suppressed TSH Dangerous? Learn the Pros & Cons

Is Having A Suppressed TSH Dangerous? Learn the Pros & Cons

Is having a suppressed TSH dangerous to your body?

Will it cause bone loss or damage to your heart?

Can the negative side effects be mitigated or avoided with other interventions?

In this post, we will discuss the pros and cons of having a suppressed TSH including what potential negative side effects it can cause, how to avoid them and how you should dose your thyroid hormone.

Let's jump in: 


What Does it Mean to Have a Suppressed TSH and is it Dangerous?

A suppressed TSH is a way to refer to a condition in the body in which the TSH is lower than it should be under "normal" conditions. 

TSH suppression occurs as a result of taking too much thyroid medication, but also secondary to certain medications conditions which cause hyperthyroidism (such as Graves' disease). 

In this article, I am going to be referring to TSH suppression secondary to the use of thyroid medication (meaning endogenous TSH suppression) because of its impact on patients who take thyroid medication. 

It is estimated that anywhere from 25 to 40% of patients taking thyroid hormone may have a suppressed or "below normal" TSH. 

The state of having a low TSH is considered to be a big problem and one that often results in Doctors altering (reducing) the dose of thyroid hormone a patient is taking. 

This is often VERY confusing to patients, especially because usually when their TSH is low they often begin to feel better form a symptomatic standpoint. 

So, from the patient perspective, why would a Doctor alter the dose of thyroid hormone if they are finally feeling better?

The answer has to do with the fact that TSH suppression is felt to lead to two potential negative side effects. 

That of bone loss and that of heart problems

But is this really a concern?

The answer may not be as clear-cut as you'd think. 

In order to have a logical and coherent and honest discussion about TSH and its impact on your health we need to answer some basic questions

Is causing TSH suppression with the use of medications the same thing as when it occurs from Graves' disease?

In other words: 

Is TSH suppression from exogenous hormone equivalent to TSH suppression from endogenous hormone?

How does the degree of TSH suppression impact the negative consequences?

In other words:

Is TSH suppression with T4 medication equivalent to TSH suppression from T3 only medications?

Is one worse than the other, are they the same?

There is evidence to believe that endogenous causes of hyperthyroidism may result in cellular hypersensitivity (especially to tissues which are sensitive to catecholamines) which may not be seen in hyperthyroidism caused by excessive dosing. 

What this means is that taking too much thyroid hormone by mouth may result in a suppressed TSH and high free T3, but this state may NOT be equivalent to the suppressed TSH and high free T3 seen in endogenous causes of hyperthyroidism such as Graves' disease. 

Thyroid adrenal reset complex 400 x 350

This phenomenon may explain why patients with endogenous causes of hyperthyroidism exhibit obvious signs of hyperthyroidism (such as weight loss, tremors, heart palpitations and so on) while patients with a suppressed TSH secondary to medication use can, and often do, experience symptoms of hypothyroidism (weight gain, fatigue, cold intolerance, constipation and so on). 

If these two conditions are the same then someone must explain how they can result in polar opposite symptoms in patients. 

Does the benefit of TSH suppression outweigh the potential negative consequences of experiencing hypothyroid symptoms for an indefinite amount of time?

In other words:

Is it better for your health long term for you to be 40 pounds overweight or would you rather lose your weight and experience a risk of 1% bone loss per year due to a low TSH?

There isn't a clear answer and the answer likely depends on the patient. 

This should be a conversation that each person has with their Doctor to determine if the risk is potentially worth taking in their individual case. 

Lastly, is there any risk of temporary TSH suppression for 3-9 months? 

In other words:

Is there any harm that will occur if you temporarily suppress the TSH in an attempt to fix or reduce symptoms or help with weight loss?

If there is no short-term risk (and I would argue that most of the risk from using T3 isn't realized until TSH suppression has been present for years) then what's the harm in a trial of altering thyroid medication?

Suppressed TSH and Bone Loss (Osteoporosis)

One of the most cited concerns for TSH suppression is the potential loss of bone or the cause of osteoporosis. 

The logic goes that suppressing your TSH will lead to an inevitable decline in bone health and an increased risk of fracture. 

Bone cells have thyroid hormone receptors and therefore they react to changes in thyroid hormone

In cases of endogenous hyperthyroidism (meaning your body produces too much thyroid hormone), patients do experience an increase in osteoporosis and fracture risk. 

This logic has lead physicians and patients to be scared of increasing thyroid dosing in fear that it may cause the same effects. 

Doctors are worried that taking too much thyroid hormone (T4) will result in the same risk that hyperthyroid patients experience. 

But is this actually observed in studies?

Sort of. 

Some studies do show that TSH suppression does cause an increased risk of osteoporosis but with 2 very important points. 

The absolute risk of osteoporosis and bone loss depends on the DEGREE of TSH suppression

For instance:

If your TSH is less than 0.1 then you will experience more bone loss than someone with a TSH in the 0.2 to 0.5 range. 

Second, this increase in risk is really only statistically relevant in women who are post-menopausal. 

Pre-menopausal women do not see a statistically significant increase in bone loss presumably due to the beneficial effects of estrogen on bone maintenance. 

But this begs a very important question:

Can the risk of bone loss be mitigated (reduced) in post-menopausal women with the use of bio-identical estrogen replacement therapy?

We don't have an answer to this because the use of hormones isn't widespread, but it may be worth considering on a case by case basis. 

Is there a risk of bone loss in post-menopausal women who use thyroxine but have a normal TSH?

The answer is no. 

So there definitely is some difference seen in women who use thyroid hormone dosing which causes TSH suppression

The question is whether or not this TSH suppression is worth it (based on your case) and whether or not you can mitigate your risk based on other therapies. 

In general:

If you are a menopausal woman (meaning you are menstruating regularly) then TSH suppression is likely not going to cause any significant risk to your bone health even if used long term. 

In the most severe cases, menopausal women with TSH suppression may realize a bone loss rate of 0.3% per year. 

But what if you are a post-menopausal woman (meaning you no longer have menstrual cycles)? 

It seems if you fall into this category then you will realize an increased risk of bone loss and osteoporosis based on how long your TSH is suppressed and how suppressed your TSH is. 

Women who fall into this category may experience up to 1% bone loss per year, which after 10 years may increase their risk of fracture significantly. 

What isn't clear, however, is if this risk can be completely reduced with the use of bio-identical estradiol and progesterone with the idea to bring these hormones back to youthful levels. 

One study showed that the combination of estrogen and suppressive doses of TSH was enough to completely negate the negative effects of thyroid hormone and normalize bone density in patients on estrogen therapy.  

This study highlights the importance of hormone control BEYOND thyroid hormone in all patients, and it highlights that physicians shouldn't necessarily be scared of a slightly suppressed TSH in all patients. 

What about the use of Calcium instead of estrogen? 

Some studies do show that supplementation with calcium, even if your TSH is suppressed, may help prevent bone loss issues. 

This study showed that the use of suppressive doses of TSH, when combined with calcium, did not have a negative impact on bone health (compared to placebo)

Does this mean that you should suppress your TSH?

Not necessarily, but it does mean that you should have a meaningful conversation about the risks vs the benefits with your current physician.  

While bone health is important, there are other factors that should be considered with TSH suppression as well, and that includes heart health. 

Suppressed TSH and Heart Problems (Atrial Fibrillation & Cardiac Enlargement)

There's no question that thyroid hormone has an impact on cardiac function and cardiac size. 

Studies have shown that thyroid hormone helps regulate the heart rate, the size of the heart and has an impact on the pressure in various chambers in the heart (including the pulmonary arteries). 

So why are Doctors and patients concerned about the heart when it comes to their thyroid?

Several studies have shown that patients with overt hyperthyroidism (such as from Graves' disease) show an increased risk of developing heart conditions such as atrial fibrillation, heart enlargement, and heart failure

It is then assumed that these complications would be seen in patients who take excessive doses of thyroid hormone by mouth for conditions such as hypothyroidism. 

The problem with this thinking is that both conditions, hyperthyroidism caused by disease states and exogenous hyperthyroidism (caused by taking too much thyroid hormone), are considered to be equivalent and the same. 

hyperthyroidism and the risk of cardiac complications

More studies are necessary to prove that this statement is in fact true. 

In the meantime, it's important to understand how thyroid hormone actually impacts the heart, especially if you are taking suppressive doses of thyroid hormone. 

What's interesting about the heart is that it only responds to T3 but it lacks the ability to alter T4 into T3 in its own tissues

This means that your heart is particularly sensitive to T3 containing medications such as Cytomel/Liothyronine and Natural Desiccated Thyroid hormone

The heart is sensitive to T4 medications but only in patients who readily convert T4 into T3 (and we know that up to 15% of people may have an issue with this conversion). 

What does this mean for you?

It means that you are more likely to experience cardiac effects when taking thyroid medications that contain T3. 

It also means that we shouldn't necessarily make general assumptions about the impact of thyroid hormone on the heart without differentiating between thyroid medications. 

So, can we look at TSH suppression and the heart the same way that we view TSH suppression and your bones?

Not exactly, but there may be some similarities. 

The impact of thyroid hormone on heart tissue depends on two important factors:

The first is the degree of TSH suppression. 

Patients with subclinical hyperthyroidism (which is NOT the same thing as overt hyperthyroidism) show only mild heart problems compared to patients with Graves' disease

The second is the length of time in which your TSH is suppressed. 

Many of the complications of hyperthyroidism, aside from heart palpitations, may take years or decades to cause an issue. 

It takes quite a bit of time for cardiac remodeling (hypertrophy) to cause gross or overt cardiac dysfunction. 

Another very important point is that several studies have shown that reducing thyroid hormone (fixing the problem) causes a complete reversal in cardiac complications (heart problems). 

In addition, other studies have shown that concurrent use of Beta Blockers can prevent AND reverse cardiac changes seen in hyperthyroid patients (particularly cardiac enlargement)

What does this mean for you?

Several things: 

It means that using TEMPORARY suppressive doses of thyroid hormone is not likely to cause any long-term cardiac complications. 

It also means that, if you are taking suppressive doses of TSH, the use of a beta blocker may be enough to completely PREVENT cardiac complications. 

There may be situations in which suppressive doses of thyroid hormone may be beneficial, but you should always consult with your physician and determine if the benefits outweigh the risks. 

It's plausible that temporary TSH suppression, with the goal of weight loss in mind, may reduce your risk of cardiac issues long-term in exchange for a temporary (and reversible) risk of cardiac issues such as heart palpitations. 

Should You Suppress your TSH? 

Dosing based on the TSH is an interesting concept and not one that is used for other hormones in the body. 

Take for instance the case of birth control pills. 

Prescribed birth control pills, when taken by mouth, act to completely shut down FSH and LH from the pituitary. 

Remember that TSH is a pituitary hormone, much like FSH and LH, but Doctors never bother to check FSH and LH when using birth control because they know that they will be suppressed. 

Birth control pills come in a standardized dose and hardly any thought is given to the degree of FSH/LH suppression when they are being used. 

Why then is the TSH given so much more weight when compared to FSH and LH? Even though BOTH hormones are secreted by the pituitary gland?

The answer isn't clear, but this is something that should be evaluated in future studies. 

We do know, as you might suspect, that there are instances when the TSH is not necessarily the best measurement of thyroid function in the body

Even though this is the case, it doesn't mean that the TSH should be ignored when dosing thyroid hormone. 

But it does mean that other factors such as Free T3, Free T4, Reverse T3 and other thyroid tests should be evaluated in conjunction with the TSH

Suppressive doses of thyroid hormone may be beneficial in some patients, but you should never adjust your thyroid dosing while dismissing the TSH entirely. 

The bottom line?

Following your TSH is an important part of thyroid hormone management, but it shouldn't be the only test you order. 

There may be some risks associated with TSH suppression (from endogenous thyroid hormone) but some of these potentially negative side effects may be avoided. 

If you are taking suppressive doses of thyroid hormone ensure that you are monitoring bone density and cardiac function. 

You can evaluate bone density with a DEXA scan and you can evaluate cardiac function with an echocardiogram

In some cases, bone loss may be prevented or avoided with the use of bio-identical hormones such as estrogen or with calcium supplementation. 

In some cases, cardiac complications may be prevented or avoided with the use of beta blockers

Your goal should NEVER be to suppress the TSH, but it may not be a serious problem if it is done correctly and only for a short period of time. 

Now I want to hear from you:

Are you currently taking suppressive doses of thyroid hormone?

Are you experiencing negative side effects associated with your TSH being low?

Do you have a low TSH but still experiencing the symptoms of hypothyroidism?

Leave your comments below! 

Westin Childs

Dr. Westin Childs is a Doctor of Osteopathic Medicine. He provides well-researched actionable information about hormone-related disorders and formulates supplements to treat these disorders. He is trained in Internal Medicine, Functional Medicine and Integrative Medicine. His focus is on managing thyroid disorders, weight loss resistance, and other sex hormone imbalances. You can read more about his own personal journey here.

Click Here to Leave a Comment Below 22 comments
Katherine - April 5, 2018

Hi Dr. Childs, I’ve suppressed my TSH to .08 in order to get my FT3 up to 3.9 from the high 2s. I did this by converting from Synthroid to Naturethroid and from there titrated a lot. It’s a hard but now at 1.5 grains via 2 doses a day. The biggest issue is hair loss and severe scalp pain this has been going on for 1.5 years now and no one knows how to treat it. I thought going up in FT3 would stop but now I”m experiencing just as much hair loss as before. The scalp also itches a lot and has produced strong pungent odors. I really need help, I’ve gone up and down the eastern seaboard to doctors. I decided to cut back 1/4 grain today to see if the hair loss stops and hair growth occurs. My hair was thick and shiny but now is thin, limp and baby hairs that do grow fall out. Please let me know if you have any experience with this. I feel so trapped in a maze.

    Westin Childs - April 5, 2018

    Hi Katherine,

    There are many reasons for hair loss among thyroid patients including the type of medication you are taking, the dose and nutrient status. You can read more about all of these factors here:

Genevieve Sulway - April 6, 2018

Hi Dr. Childs
Yes is the answer to your question about anyone experiencing hypothyroid symptoms with 0.03 TSH levels. How can this be?
I listened to your post today which was excellent and very informative about suppressed TSH.
How can this be?
Diagnosed with Hashi’s Dec 2014. Had t4 starting Levothyroxine mcg per day 50,75,100,125,159,175, over the last 3 years with fluctuations in responses.
I am pre menopausal and tested strong oestrogen levels at dec 2017.
Three months ago I started a combo of 25mcg T3 liothyronine and 100mcg euthyroid t4 as I had debilitating brain fog.
Brain fog now is gone but hypothyroid symptoms back with a vengeance. I sleep till 2 pm every day, weight gain, no energy, zero libido, hair loss and dry skin and TSH not budging past 0.05.
I don’t know what to do?

    Westin Childs - April 6, 2018

    Hi Genevieve,

    The TSH means relatively little by itself unless it is also paired with free thyroid hormones in the serum. You can learn more about how they all interact here:

amandasuzanna - April 16, 2018

Hi Dr. Childs,

Thank you for all of your great info on your website. I just recently had my labs done and my TSH was too low at 0.091 UIU/ML but my T3 and free T4 were WNL at 1.1 NG/ML and 1.5 NG/DL respectively. I don’t feel bad, by I continued to have minor symptoms across the board including resistance to weight loss on a good routine. My doc has dropped my dose, and now I am worried that I may gain more weight! Any thoughts on why too much TSH didn’t help me lose weight and why my other levels are normal when my TSH was not? I am starting some of your supplements to see if they help!!!

    Westin Childs - June 6, 2018

    Hi Amanda,

    That’s great! Keep us updated on your progress over the next few months as you use the supplements. Thanks for stopping by and sharing your story.

Julie - April 18, 2018

Hi Dr. Childs,
For yrs, I’ve bounced from Dr to Dr trying to get someone to listen to me and my symptoms of hypothyroidism. All I ever heard was your TSH is normal. Diagnosed with depression having no energy and gaining so much weight I didn’t even notice myself. My TSH has always run between 1- 2.5 with my free T4 level decreasing every check last being 0.7
Still, endocrinologist says I’m within normal range.
I finally convinced my psychiatrist to wean my antidepressant and try me on Cytomel, which within 2 weeks I felt like I woke up and had energy and less depressed. I recently had my labs checked after being on Cytomel 25 for 2.5 months. My TSH was 0.5, free T4 .67 and T3 5.
The last two weeks I feel like my energy is dropping low again and depression is worsening. I’m not sure if I need to ask my psychiatrist to increase my Cytomel dose or if my dose could be too high causing these symptoms to reappear?
Thanks for your time,

    Westin Childs - June 6, 2018

    Hi Julie,

    Adjusting your Cytomel dose, if it’s being used primarily for depression, follows different guidelines than when it is used for hypothyroidism. It’s more about your symptoms, how you are feeling and if you are experiencing negative side effects of excessive thyroid dosing.

Mary Jude - April 18, 2018

Dear Dr. Childs,
I’m a 54 yr old, postmenopausal woman, diagnosed with Hashimoto’s hypothyroidism, adrenal fatigue, insulin resistance and metabolic syndrome under the care of a functional medicine physician. However, she can’t tell me why my TSH continues to climb for a year from 4. to 12. to now 29., despite taking a regularly balanced dosage of T4 and T3 from a compounding pharmacy. This started a year ago when I began T4 and Cytomel. Currently, my T4 levels are within range, and my T3 is low. I am MISERABLE. I don’t know where to search, for an understanding of what is happening to me?

    Westin Childs - June 6, 2018

    Hi Mary,

    It’s pretty straightforward! Your demand for thyroid hormone changes as you age and as you are subjected to stressors. Normally your body can produce an increase (assuming it is functioning normally), but if it can’t then you may need to adjust your thyroid medication.

Sylvia Davies - April 19, 2018

My TSH is 0.01 my T4 25 and T3 4.6
My GP has reduced my Levothyroxine and QI am now experiencing a temperature drop, foggy mind and a lot of muscle pain which is spoiling my sleep. I am annoyed because I was feeling well before.

    Westin Childs - June 6, 2018

    Hi Sylvia,

    That’s the age-old battle that patients play with their doctors when they chase the TSH. Your doctor may have changed your medication because of your suppressed TSH. You can read more about the potential dangers of that condition here:

Grace - May 14, 2018

Hi Dr.Childs
Thanks for the redirect to this article.Yes I’m still suffering from hypothyroidism even with a suppressed TSH and being told im hyper “sigh”. Do you have any information on thyroidectomy and tendon and muscle pains and why this occurs and how to fix it ? I’m pretty crippled up with severe feet, ankle and knee pains that I can only walk or stand 15 to 30 minutes at a time I use to run half marathons and reduced to walking 10 miles per day to hardly able to stand or walk. I can’t find real reasons for this, is it because of suppressed tsh or hypothyroidism or something else? Thanks Grace

Caroline McKenzie - May 22, 2018

Hi Dr. Childs,

Thank you so much for all the very useful information.
I have just received my latest test results for tsh, ft4 and ft3. I have Hashimoto’s thyroiditis (TPO >1300) and am taking 58.3 mcg levothyroxine.
My latest blood test shows my TSH as being 0.29 (range 0.5-4.4), ft4 18.5 (10-20) and ft3 5 (3.5-6.5). I know my doctor will want to reduce my Levothyroxine due to the suppressed TSH but I have only just started to feel human again with some of my worst symptoms completely disappearing. What would you advise if you were my GP?
I am post menopausal and not on HRT.
Your comments would be greatly appreciated.

Best regards

    Westin Childs - June 6, 2018

    Hi Caroline,

    It may be best to look at other hormones to see if they could be contributing to your symptoms. Not all symptoms are related to thyroid imbalances so try to look at other hormones such as estrogen/progesterone/testosterone and cortisol.

Allie - June 23, 2018

I am taking 2 grains of armour thyroid daily. My TSH is .008. Free T3 2.8
Free at 4 1.08. I clearly need more than 2 grains of armour thyroid per day. My dr. Is worried that my TSH is too suppressed so she wants me to take synthroid and cytomel instead of armour. Thoughts?

    Westin Childs - June 24, 2018

    Hi Allie,

    This entire article is pretty much all my thoughts on the topic of suppressing TSH 🙂

Grace - June 24, 2018

Hi Dr. Childs
I’m one of those people who has been told for the past 16 months by 3 different Endocrinologist that I must have a suppressed TSH because I had Thyroid Cancer.

About 8 weeks ago my Endo called me in a panic because my TSH keeps falling along with my FT4 and FT3(Endo not concerned with FT3 or FT4 numbers) shes just focusing on the super low TSH number and the dexa scan I had 2 months prior that said I have osteopenia (mild). I was told I could “DIE” with my TSH numbers being so low,yes you read that right my Endocrinologist told me I could “DIE” from heart disease or my bones would “CRUMBLE” YUP you read that right too.

I don’t agree with her since I’ve had a life long battle with autoimmune disease that has over the course of my life forced me to use steroid injections, steroid skin preps and steroid pills in order to reduce the inflammation that consumes my body everyday and to add to this issue I was just diagnoised with Psoriatic Arthritis that has attacked the tendons in my feet and ankles and now Im on another biologic drug called (Cosyntex).

My question for you is can my 44 yrs of using steroids and now another biologic and losing my female organs 15yrs ago to cancer cause my osteopenia or could it in fact be because my TSH has been suppressed for the past 16 month? I never felt any ill effects from having suppressed TSH my biggest issue is I can not lose the 35 pounds I gained after thyroidectomy when I kept off 120 pounds for over 6 yrs prior.

Do you think I should run from this Endo she unwilling to see my other health issues and only blames my low tsh for my bone health and with each reduction of my T4 meds my P.S.A. goes nuts.

Sorry so long, Grace

Dhyanna Goulet - June 28, 2018

Dear Dr. Childs,

My TSH is 0.01, I am on 81.25 mg of Nature Throid, my TSH before taking thyroid meds was 0.015. My numbers are all mixed up.

However, when I wake up I take my pulse, it is usually around 75 to 77, then I take about half of my thyroid dose and 20 minutes to a half hour later my pulse is 72.

I have tested this over and over throughout the month and it always comes out the same.

I would love to hear from you about whether it is possible that the thyroid meds I take are making my pulse more normal?

Thank you,

Dhyanna Goulet

    Westin Childs - June 28, 2018

    Hi Dhyanna,

    Thyroid hormone does influence your heart rate and blood pressure so it is possible.

Dhyanna Goulet - July 6, 2018

Hi Dr. Childs,

On a very low tsh (.01), is it possible for my pituitary to be malfunctioning?

Some of the other clues I have that the pituitary is not working:
1. a high urine volume with inadequate antidiuretic (comes from the pituitary) hormone. I measured my urine output, should be 2.5 liters in 24 hours, mine was 1 gallon in 24 hours and I went to the bathroom 18 times. (not normal)

2. Low prolactin (produced by the anterior pituitary) The effects of altered levels of prolactin on sex hormones are profound, substantially increasing or decreasing estrogen levels. My estrogen is very high. I am 70 years old and post menopausal.

Prolactin is responsible for fluid, sodium, chloride and calcium transport and acts on the kidneys to promote sodium, potassium and water retention. (high urine output) (I use plenty of Real Salt and ‘have low blood sodium’ and naturally eat bananas every day)

I seem to have both high and low prolactin symptoms:
painful intercourse, excessive body and face hair, breast tenderness (I cannot wear a bra anymore due to pain at the lymphatic area), loss of sex drive, low energy levels, Hashimoto’s thyroiditis.

3. Pituitary problems are very common in Mercury Poisoning. I have had a provoked test for mercury, the reference range <3, mine was 75.

I believe my pituitary is damaged, if so, and the pituitary could not produce TSH, then it seems that my TSH would be non existent.

Do you think this is possible?

Thank you so much, Dhyanna Goulet


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